AutoCloseable or self-disposing temp files

[mpollmeier]

For temp files/dirs we currently rely on the JVM's deleteOnExit shutdown handler to remove them. That's not ideal though for a number of reasons, including:

• some systems may run forever, therefor never letting removing any temp files
• shutdown process is slowed down
• files stay around forever when process gets killed

There's a variety of ways we could handle this better - two that come to mind immediately are

1. implement AutoCloseable, e.g. on Path or add a new type TempPath that does it. That way users can rely on things like scala.util.Using.
2. provide our own using abstraction, similar to what better-files does - see https://github.com/pathikrit/better-files#temporary-files

Any thoughts on this?

[lefou]

I like the TempPath type very much. I would use the existing AutoClosable, so that it works with Using.

We could also add some convenience methods withTempFile and withTempDir, which I typically use in tests (https://github.com/lefou/LambdaTest#testing-files-and-directories-with-tempfile). Whereas in tests, I prefer some more fine control over the lifetime, e.g. when the test fails, I'd like to keep and print the temp file, so I can analyze it further.

[mpollmeier]

Sounds good, that'd be my preference as well. I won't be able to use a keyboard for a week or two, so unless anyone else jumps in, I'll send a PR afterwards.

[mpollmeier]

here's a first attempt: #147